A control device that is to output a driving signal to a fuel injector includes a full-lifting valve-closing response acquisition unit to acquire a full-lifting valve-closing profile indicating a valve-closing behavior of the fuel injector from a full-lifting state of a valve body constituting the fuel injector, based on a behavior of an electric signal from the full-lifting state to a closing state of the valve body, and a valve-opening response estimation unit to estimate a valve-opening profile indicating a valve-opening behavior when a valve-opening driving signal is input to the fuel injector, based on at least the full-lifting valve-closing profile.